Method and apparatus for discharging the waste as well as enhancing the flocculation of the suspension and moving the waste in solid jacket centrifuges

ABSTRACT

Method for discharging the waste and enhancing the flocculation of the suspension and the movement of the waste in solid jacket centrifuges by applying jolts to the drive means by braking or acceleration in order to open or close the waste discharge apertures and impart jolts to the compacted material. The centrifuge is equipped with a shaft through which the suspension is supplied and power transfer means such as spokes between the shaft and the drum jacket which has discharge apertures into which the ends of the spokes extend where the spokes are provided with means to open and close the discharge apertures and means for varying the speed are associated with the shaft which impart jolts to the transfer means.

United States Patent 91 Trawinski Sept. 17, 1974 METHOD AND APPARATUSFOR DISCHARGING THE WASTE AS WELL AS ENHANCING THE FLOCCULATION OF THESUSPENSION AND MOVING THE WASTE IN SOLID JACKET CENTRIFUGES [76]Inventor: Helmut Franz Trawinski,

Fasanenweg 24, D. 8452 Hirschau/Bavaria, Germany [22] Filed: Dec. 20,1971 [21] Appl. No.: 209,881

[30] Foreign Application Priority Data [56] References Cited UNITEDSTATES PATENTS Hinchley et al 233/19 R Maclsaac 233/24 Egg 233/23 R 5 7ABSTRACT Method for discharging the waste and enhancing the flocculationof the.suspension and themovement of the waste in solid jacketcentrifuges by applying jolts to the drive means by braking oracceleration in order to open or close the waste discharge apertures andimpart jolts to the compacted material. The centrifuge is equipped witha shaft through which the suspension is supplied and power transfermeans such as spokes between the shaft and the drum jacket which hasdischarge apertures into which the ends of the spokes extend where thespokes are provided with means to open and close the discharge aperturesand means for varying the speed are associated with the shaft whichimpart jolts to the transfer means.

18 Claims, 9 Drawing Figures PAIENIEDSEPWIHH 3.836.070

SHEET 1 (1F 5 mam-m PATENIEDSEP 1 7 m4 SHEET Q 0? 5 PATENTED I 3.836.070

SHEET 5 BF 5 METHOD AND APPARATUS FOR DISCHARGING THE WASTE AS WELL ASENHANCING THE FLOCCULATION OF THE SUSPENSION AND MOVING THE WASTE INSOLID JACKET CENTRIFUGES BACKGROUND OF THE INVENTION The inventionrelates to centrifuges, and particularly to the removal of waste insolid jacket centrifuges. More in particular, the invention concerns amethod and related means for discharging the compacted waste in solidjacket centrifuges by means of waste discharge apertures in the drumcasing, as well as for enhancing the flocculation of the portion ofsolid substance of the suspension to be compacted and the movement ofthe compacted waste. The field in which the invention is utilizedinvolves all suspensions from which solid components are separated bythe centrifugal force. In this connection the clearing of drain or wastewater and the separation of the solids out of suspensions in thechemical industry are mentioned merely as examples.

For discharging the waste, apertures of relatively small cross-section,like nozzles, are known in centrifuges through which the departing wasteflows uninterruptedly. Such nozzles can readily clog. Besides, the weareffects relatively large expansion of the cross section within arelatively short time. Above all, it is a disadvantage here that thecontrol or regulation of the waste discharge is not possible.

Mechanical conveyance arrangements that are complicated as to structureare known for the waste conveyance within the centrifuge. Centrifugesare also known whose jacket that surrounds the sedimentation space isdisposed conically where the inclination of the cone to the longitudinalaxis of the centrifuge is rela tively large. The compacted waste orslurry here can slide under the effect of the centrifugal force in thedirection of the outlet. A drum jacket of such conical shape involvesthe shortcoming that its greatest outer diameter must be rather large inrelation to the diameter of the liquid level of the circulatingsuspension which with a certain centrifuging effect results inrelatively high centrifugal forces in the region of the liquid level atthe outer diameter of the jacket. Thereby also the effective clearingsurface area is reduced which is obtained as the product of thecylindrical surface of the fluid level and the acceleration factor.

It is known with solid jacket centrifuges having a continuous overflowstream to add highly molecular flocculating agents and to essentiallyreduce the rotational speed of the motor in order to increase theclearing effect. However, this involves the disadvantage of expensiveconstruction and long mixing stretches in order to bring the solidparticles of the suspenion and the chain molecule aggregates of theflocculating agents in intensive contact with each other.

SUMMARY OF THE INVENTION It is an object of the invention to effect witha single process measure while avoiding the above shortcomings, thedischarge of the compacted waste in a regulated and controlled manner bymeans of waste discharge apertures, as well as also to promote themovement of this waste within the drum jacket and the flocculation ofthe solid substance parts in the suspension. In connection with this,also the method of the feeding of the suspension supply is to beimproved. The means required for carrying out this method are to be ofsimple construction.

In order to solve this problem, the invention proposes first as ameasure of the method that by braking or accelerating jolts upon thedrive the waste discharge openings are opened and again'closed, and thecompacted waste is subjected to jolts in a direction that is tangentialto the drum jacket. These jolts are applied to the centrifuge thatrotates at rated speed so that no larger kinetic energies have to beintroduced or destroyed. The waste discharge openings may be relativelylarge in cross section. Control or regulation of their opening time andthe duration of the intermediate closing periods can be readily obtainedby suitable control or regulation of the braking or acceleration jolts.

Furthermore, these jolts impart shearing forces and a fine turbulence tothe suspension. In this manner the flocculation is enhanced and thatwith the addition of flocculating material, as well as also inconnection with the self-flocculation of the suspension.

The braking or accelerating jolts may furthermore be made of suchmagnitude that in addition they effect, or at least promote, releasingof the limit layer between deposited waste and the inner wall of thedrum jacket; Interfering re-whirling of the sedimented particles neednot be expected because the jolts in accordance with the invention occurat intervals of such length that between two jolts there is sufficienttime that the interference impulses due to the internal friction of thecarrier liquid can dampen out and are not effective until theoverflowing of the liquid occurs. The adhesion friction between thedisposed waste and the inner wall of the drum jacket is, however,reduced by the jolts so that the migrating of the waste along thesedimentation section of the drum jacket is enhanced in the directiontoward the waste outlet. Thus, it is not necessary as with knowncentrifuges to provide the sedimentation section of the drum jacket witha strongly inclined taper toward the axis of the centrifuge.

The aforementioned shearing forces decrease due to the braking andaccelerating jolts from the drum jacket inwardly in the direction of theliquid level of the suspension load that surrounds the drive shaft. Forthe further enhancement of the flocculation in the entire area of thesuspension load the invention further provides that the circumferentialvelocity of the entering suspension supply is greater or smaller thanthe suspension load that is already in the centrifuge, while thesuspension supply is introduced in the same direction of rotation as thecirculation of the suspension load. The difference of speed resultinghere between the suspension supply and the suspension laod effects afurther increase of the flocculation and that most strongly in theproximity of the liquid level of the suspension supply. This effectdecreases in the direction toward the drum jacket and thus supplementsin an advantageous manner the flocculating effect of the braking and theaccelerating jolts described above. In a like manner as the strength andduration of the braking accelerating jolts, the difference in velocitybetween the suspension supply and the circumferential velocity of thesuspension load can be varied by regulating. Besides, these two factorsare adjustable relative to one another in the cycle of the change. Thus,one can adapt ones self to existing operating conditions and thus obtainoptimum flocculation effects and clearing results.

The inventionfurthermore concerns an arrangement for carrying out theexplained method where the driving moment is initiated by a shaft withthe aid of transfer elements in the drum jacket. For this purpose, theinvention provides that in addition to the drive, a braking oraccelerating means is provided that acts upon the shaft. These may be inthe form of braking or coupling members that can be rapidly connectedand disconnected which act on the drive shaft or on rotating machineparts that are rigidly or elastically coupled therewith. Examples ofsuch braking or coupling elements are friction couplings that can bebrought into engagement with non-rotating machine elements or such having a lower or higher speed of a sufficient moment of inertia that maybe variable, furthermore mechanical brakes, magnetic brakes, eddycurrent brakes, brake generators, and the like. In this connection thedifferent moments of inertia-of the drum jacket and the driving star canbe utilized. The intensity and the duration of the braking oraccelerating jolts can be chosen in accordance with the accumulatingwaste.

The opening and closing of the waste discharge openings by means ofbraking and acceleration jolts can be realized in different ways. Inaccordance with a preferred embodiment of the invention, a driving starrigidly connected with the drive shaft serves as transfer element inthis connection which is tumable by a limited angle relative to the drumjacket and in force transferring engagement at its free ends with thedrum jacket in both directions, directly or indirectly by means ofratchets or stop abutments, while in the phase of the driven course andthe accelerating jolt, the waste discharge openings are closed by meansof the free ends of the driving star, or covering devices providedthereon, while they are open after rotation of the driving star as aresult of a braking jolt or a non-driven run. Thus, depending on itsangular position, the driving star effects the opening or closing of thewaste discharge openings.

The increase or decrease of the number of rotatiions of the supplysuspension can be obtained in different ways. In accordance with apreferred embodiment of the invention the outflowing clear liquid of thecentrifuge serves for this purpose while this clear liquid has impartedto it the increased or decreased number of rotations by means of apaddle wheel device. The particu-' lar turbine wheel of this device iscoupled with the supply or feed device of the suspension supply, forexample a sleeve.

BRIEF DESCRIPTION OF THE DRAWINGS Further advantages and features of theinvention will appear from the following description of severalembodiments with reference to the respective drawings which areessentially schematic and in which FIG. 1 shows a longitudinal sectionof the centrifuge in accordance with the invention with two differentdevices for obtaining a brake jolt,

FIG. 2 is a longitudinal section of an embodiment of the drum jacket,

FIGS. 37 are cross sections of different possibilities for closing andopening the waste discharge openings taken about along the line AA inFIG. 2, and

FIGS. 8 and 9 are longitudinal sections of embodiments of hydraulicaccelerating devices for the supply suspension.

DESCRIPTION OF THE INVENTION The application of the method in accordancewith the invention is not limited to the embodiment illustrated. Inaccordance with the invention the embodiment of a solid jacketcentrifuge illustrated in FIG. 1 comprises, among other things, a driveshaft 1 and the drum jacket which in principle consists of the centralwaste collecting part 2 and the sedimentation parts or sections 3, inwhich connection the waste discharge openings are indicated at 5 and theover-flows for the clear liquid at 21. In the present example this is acontinuously operating removal device for the clear liquid, preferably arotation symmetric overflow weir. The suspension supply is fed, inaccordance with arrow 6, through the interior of the shaft 1, whence itreaches through its openings 7 the supply means serving for itspreliminary acceleration, which in this case is a sleeve 8a, and finallythrough the discharge apertures 8b thereof the rotating suspension load,the level and load of the centrifuge being indicated in dot and dashlines. Construction and effect of this sleeve as well as of its driveare explained in detail hereinafter.

The moment of rotation of the shaft 1 is passed on by a transferelement, in this case a driving star 9, to the jacket of the drum 2, 3.A coupling or braking device 10 serves for the braking of the shaft 1for a short period of time. The additional initiation of theinterference with the moment of rotation for causing a braking oracceleration jolt can, in accordance with the illustration in FIG. 1,lower right, also be realized in that a coupling 22 that rotates withthe shaft 1 and is connected therewith can be brought into engagementfor a short period of time with a rotating braking element 23. Thiselement has a moment of inertia (fly wheel effect) which, as compared tothe inertia effect of the rotating system, i.e., the actual centrifuge,constitutes a worthwhile partial amount of, for example, 5 to 10percent. The number of rotations of the braking element 23 is less thanthat of the rotating system. As soon as the coupling is brought intoengagement with it, the inertia moment of the braking element 23 must bebrought to the full number of rotations of the rotating system with ashock or jolt. Since no additional driving energy is introduced, anumber of rotations is established in a shortest manner, which isdisposed between the original number of rotations of the rotating systemand that of the rotating braking element 23. The moment of inertia ofthis braking element 23 can still be increased in that it is equippedwith a non-centrifuge regulator, which at the moment of the coupling,and therefore with increase of the number of rotations, effects a suddenor jolt-like increase of the moment of inertia of the braking element 23(not-illustrated). In this manner the intended aim of a sudden orjolt-like reduction in numbers of rotation of the rotating system isobtained to an increased extent without a large rotating mass. Thebraking element 23 is journalled on the shaft 1 by way of ball bearing24 and can be held at its reduced number of rotations by a specialdrive, not illustrated in the drawings, for example a friction drivewhich is automatically separated as the coupling engages.

A sudden change of the velocity of the driving star 9 of the rotatingdrum jacket, whether it be by brief operation of a brake or by a shorttime increase of the drive moment and the termination of this change inspeed, can effect the described braking and acceleration jolts. By thesemeans the opening and closing of the waste discharge openings iscontrolled. This is explained in detail with reference to FIGS. 3 to 7.

Additionally there results the enhancement of the flocculation and atcorresponding strength of the jolt also the effect of an axial movementof the condensed waste out of the sedimentation sections 3 of smallerdiameter to the collecting section 2 of larger diameter of the drumjacket. With each braking or acceleration jolt there results atangential displacement of the inert waste on the inside of thesedimentation sections 3. This is sufficient for eliminating theretaining forces between the waste and the inside surface and theintended axial movement by utilizing the centrifugal force also with arelatively small inclination of the comers defined by the sedimentationsection which opens in the direction of the collecting part. The ratioof the outer diameter 144 of the sedimentation section 3 to the diameterof the liquid level of the rotating suspension load is favorable (seealso FIG. 2). This effect can still be increased by guide worms havingone or several grooves or scoops 12 or shutter-like claws 13 which arerigidly connected with the sedimentation section 3, for example bywelding. During the braking phases the waste slides in steps to theflanks of the worms, moving helically in the direction of the wastecollecting part. If worms or claws of this type are used, thesedimentation sections 3 may even be cylindrical in shape, if the joltsare sufficiently strong.

The waste collecting part 2 has a cylindrical section 16 centrallythereof with waste discharge openings 5 and two walls 17 laterallythereof having steep conical form, on which the waste can slideoutwardly without auxiliary transport means. The sedimentation section 3may, as indicated at 18, be releasably threaded together with the frontends of the waste collecting section 2, and are thus readilyexchangeable with other sedimentation sections, for example, ofdifferent inclination or magnitude.

With this form of construction of the drum jacket the spokes 19, 20 thatare supported on bearings on the shaft may be provided relatively closeto the center of the centrifuge on both sides of the driving star 9.Thus also the discharge openings 8b of the supply device 8a may benearly at the center of the centrifuge. The discharge openings 8b aredirected outwardly and simultaneously to the collecting section 2,-sothat more solid and thick waste parts reach the bottom of the wastecollecting space as rapidly as possible, i.e., the inside of the wall16. In addition it is advisable to have the outlet openings mergeproximate the surface of the suspension load.

As a further development in accordance with the invention the transferelement which effects the transfer of power to the drum jacket carriesor constitutes the covering devices for the waste discharge openings. Inaccordance with a further development of the invention a structurallyparticularly simple and effective arrangement for the transfer of thebraking or acceleration jolt to the drum jacket is that the drive star 9is not rigidly connected with the drum jacket 2, 3, but is turnablethrough a limited angle relative thereto and comes into engagement withits free ends with the drum jacket in both directions of rotationdirectly or by way of ratchets or stopping abutments. If the shaftdriven at a normal number of rotations and the drive star rigidlyconnected with it is suddenly braked, then the power transfer betweenthe drive star and the drum jacket is interrupted, and the drive starmoves backward by the aforementioned angular amount relative tothedirection of rotation due to the greater inertia of the drum jacket,because due to its greater mass inertia the drum continues to move withalmost the same angular velocity. The larger the angle of rotation is,the larger will be the braking jolt. If the brake is released, the drivestar snaps back to the initial position due to the full driving forcethat is again imparted to it by the shaft, and again comes into forcetransmitting engagement with the jacket of the drum. Such jolts can alsobe obtained by sudden acceleration or retardation of the drive itself.

As the drive star is turned through a certain angle relative to the drumjacket, the waste discharge apertures are closed during the phase of thedriven run and of the acceleration jolt by the free ends of the drivestar, or are closed by the covering devices thereon, while on the otherhand they are closed after turning of the drive star as a result of abrake jolt or a delay in the drive.

For this purpose FIG. 3 shows cams or projections 4 that extend inwardlyfrom the drum jacket, which on one side constitute the driver 4' and ontheir other side the stopping abutment 4' Besides, the waste dischargeopenings 5 pass through these cams or projections 4 and open up at theabutment side 4'. In this manner the ends of the drive stars or theircovering devices can during the closing phase sealingly engage theabutment side 4 with their sealing surfaces 9. The apertures 5 areclosed. Moreover, in accordance with FIG. 3 they are directed oppositeto the driving direction indicated by the arrow.

If the shaft 1 is braked, the drive star remains behind and comes intoengagement with its surface 9" with the counter surface 4" of the nextcam or abutment that constitutes the stopping abutment. During thisrelease of the openings 5 the waste can emerge. If the braking of shaft1 is discontinued, then the drive star 9 again runs ahead and arrives inthe position illustrated. The angle or passed through by the drive stararms can be chosen to be of different size as long as the wastedischarge is insured.

In the embodiment in accordance with FIG. 4 the drive star arms 9 aretiltably mounted in the direction of rotation by a limit angle B, on acollar 28 of the shaft 1, whereby a corresponding relative movability ofshaft 1 with respect to the drum jacket is obtained. The free ends ofthe drive star arms extend into the waste discharge openings 29 of thedrum jacket. During normal operation in the direction of rotation theapertures 29 are opened (illustration in solid lines). As the shaft 1 isbraked, they tilt about the angle B and due to the change of the angleof penetration, they partly open the slot-like apertures 29(illustration in dashed lines). The surface of the collar is soconstructed that it limits the tilting of the arms but at the same timepermits it through the angle [3.

In order to obtain a better sealing effect and also in order to dampenthe acceleration and braking jolts, there may be elastic dampening meansat the drivers or stopping abutments, respectively the correspondingsurfaces of the drum jacket or on associated abutment surfaces of thedrive star arms. One possible embodiment of this dampening isillustrated in FIG. 5. The drive star arms 9 are provided with sealingelements 30 which during the starting phase come into engagement withthe counter surface of the slot 31 of the drum jacket. The opposite sideof the waste discharge opening is closed by an elastic deformable seal32 which serves at the same time for the dampening of the jolt. With abraking jolt these members 32 are compressed and free a passage for thewaste between the sealing e]- ement 30 and the surface of the slot 31.

In the embodiment in accordance with FIG. 6 the drive star arms 9 areprovided with sliding shoes 33 which are surrounded by a sealingmaterial 34. During the starting phase they are in engagement with thedrive edge 36 of the drum jacket and thus seal the slot 35. During thebraking phase, however, they are in engagement with the rearwardstopping abutment 37 and thus open the slot 35.

Furthermore, it is possible to control or regulate the position of thecovering device of the waste discharge openings by coaction of the forceof inertia and the centrifugal force, in which connection the openingand closing of the waste discharge openings is effected by a change inthe force of inertia, which likewise results from braking oracceleration jolts. This is explained more in detail in the embodimentof FIG. 7. The drive star 27 performs the task of a spoke cross, and forthis function it is firmly connected with the jacket of the drum. It isprovided with angularly shaped tilting levers 38 which are pivotallyconnected to it and which have counter-Weight arms 38 that extendinwardly. During the driving phase the counter-weight arms stay back dueto their inertia, so that the outer arms of the levers 38 close thewaste discharge openings 39. During the braking phase, however, theinertia effects the tilting of these levers and thus the freeing of theopenings 39 for the discharge of the waste. As a result of a new drivingjolt the position illustrated is restored.

The cross-section of the waste discharge openings can be made relativelylarge, because the invention provides on the. one hand relatively shortopening periods, for example fractions of a second, and on the otherhand longer time intervals between two opening phases, for examplefractions of a minute. Thus the time intervals between two jolts in thiscase are large in relation to the duration of the individual jolt. Largecrosssectional openings of the waste discharge nozzles or slots,however, are desirable, because they can be produced in essentiallysimpler fashion than nozzles or slots of smaller diameter. Also, thedanger of clogging is less. To this is added that the wear thatnecessarily results with the discharge of the waste requires arelatively larger cross-sectional expanse for discharging the materialsurrounding the aperture at a smaller diameter of the opening than withapertures of larger diameter. The number of waste discharge openings ofa centrifuge may be small, as shown in the drawings.

The invention also insures faultless discharge 0 smaller wastequantities, because the discharge is not continuous but takes place onlyduring predetermined opening intervals which are interrupted by theclosing intervals. Also, the separating of larger quantities of waste ispossible because discharge openings of large cross-section are provided.As explained, the length of the closing and opening intervals can becontrolled. In accordance with the invention it is preferable to provideregulation corresponding to the accumulating waste. This can be effectedby the photocell 25, which in accordance with FIG. 2 is located in aplace below the actual over-flow 21 or a secondary over-flow 26, andeffects the opening of the waste discharge apertures as soon as acertain opaqueness or turbidity has developed. In this manner it isassured that only clear liquid overflows.

The secondary over-flow 26 consists of one or several bores which arelocated at the circumference below the liquid level. By these means itis accomplished that a small portion of the over-flow stream flows offcontinuously. As soon as opaqueness occurs at this location, anindication is provided that the waste level has grown beyond the levelof the actual waste collecting space that is limited by the walls 17.This makes possible the connecting of the regulating means before theactual main over-flow becomes turbulent.

The means for supplying the suspension to the interior of the drum canbe constructed in different ways, for example, in' the form of asprinkler. In accordance with the above mentioned preferred embodimentthe supply device is in the form of a pre-accelerating tube. Thesuspension enters through the socket-like exit openings 8b of the sleeve8a into the cylindrical surface with the load suspension rotating aboveor below the velocity. The difference of the number of rotations may beattained by driving the pre-accelerating tube 8a of a particularindependent drive shaft, for example a gear belt or chain drive. Also,the derivation of an additional moment of rotation is possible below thechange of number of rotations of the shaft 1 by means of a gear unit 11or a planet gear.

The change of the number of rotations of the preaccelerating tube 8awith respect to the speed of the drive shaft 1 can be obtained by usingthe over-flow stream of the centrifuge also with the aid of a hydraulicdevice.

Such an arrangement is illustrated in FIG. 8. It is provided at one ofthe two sedimentation sections 3 of the drum jacket and imparts to thesupply suspension flowing out of the pre-accelerating tube a higherspeed of rotation than the rotational speed of the suspension loadrotating in the drum jacket. In addition, the clear liquid is suppliedby way of the over-flow wier 21 to the interior of a paddle wheel 41which is firmly connected with the sedimentation section 3. The clearliquid is conducted through the paddle wheel 41 outwardly to its largestdiameter, and thereby accelerated to a rotational speed that is greaterthan the rotational speed in the area of the overflow wier. The energyrequired for this purpose is provided by the shaft 1 by way of thesedimentation section 3. The paddle wheel 41 is closed at both sides.Thus the clear liquid at the periphery of this wheel enters the annularspace 43, which is devoid of paddles, located opposite a separating wall42, in that it is conducted back inwardly. There results, due to theconstrained construction of a Helmholtz-flow turbulation, an increase ofthe number of rotations and thereby a renewed increase of thecircumferential velocity. Finally, the clear liquid thus acceleratedleaves the rotor system that rotates with the drum jacket and isconducted into the interior of a turbine wheel 44 which is firmlyconnected to be carried along with the pre-accelerating tube 8a. Theflowing of the clear liquid through the turbine wheel imparts thereto anincreased velocity that is transferred to the tube 8a. The

liquid that leaves at the outer circumference of the turbine wheel 44 isconducted away'by means not illustrated. I

The increase of the circumferential speed of the supply suspensionexplained above obtains the further effect that due to its increasedcentrifugal force, it advances rapidly from the intake into the liquidlevel of the load suspension to the drum jacket.

However, it would also be possible to impart to the pre-acceleratingtube and thereby to the supply suspension a velocity that is decreasedwith respect to the rotating speed of the drum jacket and of the loadsuspension. For this the simplified arrangement can be used that isillustrated in FIG. 9. The over-flow liquid is conducted directly to theoutside in accordance with the arrow, by way of a turbine wheel 45rigidly connected with the pre-accelerating tube 8a. Due to the increaseof its radius, the liquid has imparted to it during an unchangedcircumferential velocity a decreased number of rotations, as compared tothe rotating drum jacket and the load suspension which is transmitted tothe preaccelerating tube.

Having now described my invention, what I desire to protect by letterspatent of the United States is set forth in the appended claims. 1

1. Method for discharging the compacted waste from solid jacketcentrifuges provided with drive means by way of waste dischargeapertures in the jacket of the drum of the centrifuge, as well as forenhancing the flocculation of thesolid portion of the suspension to becompacted and of the movement of the compacted waste, said methodcomprising the steps of opening the waste discharge apertures byapplying jolts to said drive means by braking or acceleration to openand close the waste discharge apertures and imparting jolts to thecompacted waste material in a direction tangential to the jacket of thedrum.

2. Method in accordance with claim 1, where for the further enhancementof the flocculation by a decrease in velocity the circumferentialvelocity of the entering supply suspension is made greater or smallerthan that of the load suspension which is already stationary in thecentrifuge, while the supply suspension is introduced in the samedirection of rotation as the rotation of the load suspension anddischarging waste through the apertures in the drum.

3. Apparatus for discharging the waste as well as enhancing theflocculation of a suspension and the movement of the waste in solidjacket centrifuges, comprising a centrifuge having a drum jacketprovided with waste discharge apertures, a shaft having force transfermeans such as arms extending to said apertures and having ends adaptedto open and close said apertures, and means associated with said shaftoperative to change the rotational speed by braking or acceleration andthereby open said apertures and impart jolts to the waste materiaL.

4. Apparatus in accordance with claim 3, where the outer ends of saidtransfer means present cover devices for the waste discharge apertures.I

5. Apparatus in accordance with claim 4, where said transfer means is inthe form of a driving star connected to said shaft for movement througha limited angle relative to said drum jacket and said drum jacket havingabutment means proximate said apertures for engagement by said coverdevices and means whereby during the running phase said apertures areclosed, while upon change in the angular position resulting from thechange of the speed of said shaft and resulting jolts said apertures areopened.

6. Apparatus in accordance with claim 5, comprising projectingconfigurations such as cams defining on one side driving configurationssuch as ratchets or the like, and on the other side stopping abutments.

7. Apparatus in accordance with claim 6, where the waste dischargeapertures pass through said projections and are open at the ratchet sideand the ends of said driving star are provided with sealing surfaceswhich are engagement with said apertures during aperture closedoperation.

8. Apparatus in accordance with claim 5, where the free ends of saiddriving stars extend into said waste discharge apertures and ends ofsaid driving stars and the waste discharge apertures are provided withsealing surfaces that are in engagement with each other during apertureclosed operation.

9. Apparatus in accordance with claim 7, where jolt dampening means areprovided intermediate said ratchets and said stopping abutments on theone hand and the ends of said driving stars on the other hand.

10. Apparatus in accordance with claim 4, comprising covering devicesoperatively responsive to inertia forces pivotally mounted proximatesaid apertures and having arms responsive to centrifugal forces to closesaid apertures and in response to jolts applied through said shaft toopen said apertures.

11. Apparatus in accordance with claim 10 where said centrifuge includesoverflow means and a photocell proximate said overflow means formeasuring the turbidity of the fluid to thereby control the duration ofthe closing intervals and the opening periods.

12. Apparatus in accordance with claim 11 where said drum jacketcomprises a central waste collecting section and two sedimentationsections connected to said collecting section and where said wastedischarge apertures and the force transfer means are disposed in saidcollecting section.

13. Apparatus in accordance with claim 12 where means are provided onsaid drum jacket in said sedimentation sections such as guide worms,scoops, claws or the like, while the sedimentation sections arecylindrical or of small inclination relative to the axis of saidcentrifuge and open toward said collecting section, and said collectingsection is provided with side walls steeply inclined relative to theaxis of said shaft.

14. Apparatus in accordance with claim 3 comprising a supply device forintroducing a pre-accelerated supply suspension disposed coaxially withrespect to said shaft and rotatable therewith in the same direction atincreased or decreased numbers of rotation.

15. Apparatus in accordance with claim 14, where said supply devicedefines a pre-accelerating means in the form of a tube having dischargeopenings for the supply suspension that are directed outwardly towardsaid collecting section to discharge proximate the surface of the loadsuspension.

16. Apparatus in accordance with claim 14 comprising a hydraulic drivemeans for said supply device separated by means of the overflow streamfrom said centrifuge.

17. Apparatus in accordance with claim 16, where said supply deviceincludes a paddle wheel connected with the sedimentation section of thedrum jacket for rotation therewith to impart acceleration to the supplydevice, said wheel having an intake and an outlet for the overflowstream of clear fluid, an annular space connected to said outlet adaptedto return clear fluid inwardly, a turbine wheel in the annular spacethrough which flows the clear liquid from said annular space outwardlyand connected to said supply device for rotation therewith.

directly connected with the supply device.

1. Method for discharging the compacted waste from solid jacketcentrifuges provided with drive means by way of waste dischargeapertures in the jacket of the drum of the centrifuge, as well as forenhancing the flocculation of the solid portion of the suspension to becompacted and of the movement of the compacted waste, said methodcomprising the steps of opening the waste discharge apertures byapplying jolts to said drive means by braking or acceleration to openand close the waste discharge apertures and imparting jolts to thecompacted waste material in a direction tangential to the jacket of thedrum.
 2. Method in accordance with claim 1, where for the furtherenhancement of the flocculation by a decrease in velocity thecircumferential velocity of the entering supply suspension is madegreater or smaller than that of the load suspension which is alreadystationary in the centrifuge, while the supply suspension is introducedin the same direction of rotation as the rotation of the load suspensionand discharging waste through the apertures in the drum.
 3. Apparatusfor discharging the waste as well as enhancing the flocculation of asuspension and the movement of the waste in solid jacket centrifuges,comprising a centrifuge having a drum jacket provided with wastedischarge apertures, a shaft having force transfer means such as armsextending to said apertures and having ends adapted to open and closesaid apertures, and means associated with said shaft operative to changethe rotational speed by braking or acceleration and thereby open saidapertures and impart jolts to the waste material.
 4. Apparatus inaccordance with claim 3, where the Outer ends of said transfer meanspresent cover devices for the waste discharge apertures.
 5. Apparatus inaccordance with claim 4, where said transfer means is in the form of adriving star connected to said shaft for movement through a limitedangle relative to said drum jacket and said drum jacket having abutmentmeans proximate said apertures for engagement by said cover devices andmeans whereby during the running phase said apertures are closed, whileupon change in the angular position resulting from the change of thespeed of said shaft and resulting jolts said apertures are opened. 6.Apparatus in accordance with claim 5, comprising projectingconfigurations such as cams defining on one side driving configurationssuch as ratchets or the like, and on the other side stopping abutments.7. Apparatus in accordance with claim 6, where the waste dischargeapertures pass through said projections and are open at the ratchet sideand the ends of said driving star are provided with sealing surfaceswhich are engagement with said apertures during aperture closedoperation.
 8. Apparatus in accordance with claim 5, where the free endsof said driving stars extend into said waste discharge apertures andends of said driving stars and the waste discharge apertures areprovided with sealing surfaces that are in engagement with each otherduring aperture closed operation.
 9. Apparatus in accordance with claim7, where jolt dampening means are provided intermediate said ratchetsand said stopping abutments on the one hand and the ends of said drivingstars on the other hand.
 10. Apparatus in accordance with claim 4,comprising covering devices operatively responsive to inertia forcespivotally mounted proximate said apertures and having arms responsive tocentrifugal forces to close said apertures and in response to joltsapplied through said shaft to open said apertures.
 11. Apparatus inaccordance with claim 10 where said centrifuge includes overflow meansand a photocell proximate said overflow means for measuring theturbidity of the fluid to thereby control the duration of the closingintervals and the opening periods.
 12. Apparatus in accordance withclaim 11 where said drum jacket comprises a central waste collectingsection and two sedimentation sections connected to said collectingsection and where said waste discharge apertures and the force transfermeans are disposed in said collecting section.
 13. Apparatus inaccordance with claim 12 where means are provided on said drum jacket insaid sedimentation sections such as guide worms, scoops, claws or thelike, while the sedimentation sections are cylindrical or of smallinclination relative to the axis of said centrifuge and open toward saidcollecting section, and said collecting section is provided with sidewalls steeply inclined relative to the axis of said shaft.
 14. Apparatusin accordance with claim 3 comprising a supply device for introducing apre-accelerated supply suspension disposed coaxially with respect tosaid shaft and rotatable therewith in the same direction at increased ordecreased numbers of rotation.
 15. Apparatus in accordance with claim14, where said supply device defines a pre-accelerating means in theform of a tube having discharge openings for the supply suspension thatare directed outwardly toward said collecting section to dischargeproximate the surface of the load suspension.
 16. Apparatus inaccordance with claim 14 comprising a hydraulic drive means for saidsupply device separated by means of the overflow stream from saidcentrifuge.
 17. Apparatus in accordance with claim 16, where said supplydevice includes a paddle wheel connected with the sedimentation sectionof the drum jacket for rotation therewith to impart acceleration to thesupply device, said wheel having an intake and an outlet for theoverflow stream of clear fluid, an annular space connected to saidoutlet adapted to return clear fluid inwardly, a turbine wheel in theannular space tHrough which flows the clear liquid from said annularspace outwardly and connected to said supply device for rotationtherewith.
 18. Apparatus in accordance with claim 16 where saidhydraulic drive means includes a turbine wheel and for reducing thenumber of rotations of said supply device the clear liquid is conductedfrom the inside outwardly to said turbine wheel and said turbine wheelis directly connected with the supply device.